1. The Field of the Invention
The present invention relates generally to extendable and retractable cover systems, and more particularly, but not entirely, to a dual-shaft drive mechanism for flexible pool covers that may be activated using a portable low voltage power source.
2. Description of Related Art
Swimming pools and related structures are extremely popular. Commercial and residential swimming pools typically consist of a water containment vessel that may reside below ground or above ground, including water-impermeable walls and a bottom surface.
In many circumstances, it is desirable for the user to place a protective barrier or pool cover over the pool when the pool is not in use. Such a pool cover serves many functions: it helps to conserve water normally lost through evaporation, it can prevent water contamination resulting from outside debris, it saves water treatment costs by reducing chemical loss, and it saves energy loss by retaining heat energy in the water. Perhaps most importantly, a properly installed pool cover that provides a safety feature can prevent accidental drowning of persons falling into the pool area.
While many pool cover devices have been developed, most are awkward and difficult to install and remove, thereby discouraging their use and inhibiting their benefits. Such devices require a high-torsion power source, or a manually-operable crank arm, and are therefore cumbersome and laborious to operate. Further, many of these devices require a user to act at both ends of the pool to cause the pool cover to be extended and retracted, an inconvenience which may discourage use of the pool, or worse, result in the pool being left uncovered.
Some pool cover devices known in the prior art, are those disclosed in U.S. Pat. No. 5,913,613 (granted Jun. 22, 1999 to Ragsdale, et al.), in U.S. Pat. No. 4,811,433 (granted Mar. 14, 1989 to MacDonald, et al.), in U.S. Pat. No. 4,459,711 (granted Jul. 17, 1984 to Sartain, et al.), and in U.S. Pat. No. 5,890,240 (granted Apr. 6, 1999 to Graham), among others. The Ragsdale and Macdonald references disclose devices that require major modification to an existing pool to prior to installation. An enclosure must be constructed to hold a pool cover system including multiple reels, shafts and a permanent electric motor. These systems require that electric lines which encumber the enclosure, and a separate control must be placed elsewhere. As a result, such devices can be expensive to manufacture and install. Installation of such a device is often too complex for a pool owner to attempt alone. Additionally, should the electricity go out, the pool cover may not be able to be opened or closed, until power is restored. Further they present the dangers of having an electric power line close to water to users of the pool.
The types of devices disclosed in Sartain and Graham constitute attempts to resolve some of the problems discussed above. A device such as the one shown in Graham has resulted in a pool cover system in which the drum moves along the pool or pool deck to roll up the cover. Since the cover is not fixedly attached to the pool deck, the Graham device fails to provide a safety cover. Similarly, Sartain fails to provide a cover having a high degree of safety allowing the pool to be unsafe even when covered.
Further, as a pool is covered or uncovered with a Graham type device using a portable drill, the user is required to walk alongside the device in an awkward position for the length of the pool. This inconvenience discourages use of the cover.
While Sartain teaches the use of a hand crank located at one end of the pool for the purpose of both covering and uncovering the pool, it still requires the user to attach a line to the cover, walk the line across the open pool, and then place the line through a system of pulleys located on the pool deck, discouraging use of the cover. Additionally, the amount of force needed to turn the crank prevents many users from covering and uncovering the pool without assistance when using a Sartain-type of device.
It is noteworthy that none of the prior art known to applicant provides a pool cover system with a safety cover that may be easily activated by a single user, that utilizes a low voltage portable power source, that is relatively inexpensive to make, simple in operation and installation, and that is completely operable from a single end of the pool by a single user.
The prior art is thus characterized by several disadvantages that are addressed by the present invention. The present invention minimizes, and in some aspects eliminates, the above-mentioned failures, and other problems, by utilizing the methods and structural features described herein.
It is therefore an object of the present invention to provide a pool cover system that is relatively easy to operate.
It is also an object of the present invention, in accordance with one aspect thereof, to provide a pool cover system that provides a safety cover that may be operated by a single user from one end of a pool.
It is a further object of the present invention, in accordance with one aspect thereof, to provide a pool cover system that provides a safety cover, but does not require major modification of the pool deck.
It is another object of the present invention to provide such a pool cover system that is operable from a single end of a pool with only a low-torsion, low-voltage power source for operation.
The above objects and others not specifically recited are realized in a specific illustrative embodiment of a pool cover system including an apparatus for retracting a pool cover from over a pool, or extending a pool cover over a pool. The system includes a pool cover collecting drum supported for rotation on its ends, and a drive gear connected to the drum by a drive shaft. A power gear for engaging the drive gear is operably connected to a portable, battery operated electric drill by a power shaft. When the drill is activated, the drive gear rotates the pool cover collecting drum to collect and retract the pool cover from over the pool. The pool cover is placed back over the pool by utilization of a complementary apparatus on the same side of the pool, such as a rope reel collecting apparatus including an engageable drive gear and a drive shaft connected to a reel, to extend the pool cover over the pool by pulling on a rope attached to a rigid end or carrier of the pool cover. The sides of the pool cover are fed through, and supported by, a dual channel track. As the pool cover is extended and retracted it slides in one channel of the dual channel track, allowing the cover to serve as a safety cover. The gears may be located in a sealed housing filled with lubricant. It is preferred to locate the drive shafts of the cover collection apparatus and the rope reel collection apparatus in a co-linear parallel fashion with one residing directly above the other. The drive shafts may include a universal joint, and the drill may be designed to engage the power shaft with a flexible socket adapter.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by the practice of the invention without undue experimentation. The objects and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims.